# -*- coding:utf-8 -*-
# the first print test

#a = 100
#if a >= 0:
#    print a
#    print 'adult'
#else:
#    print -a

#age = 3
#if age >= 18:
#    print 'your age is',age
#    print 'adult'
#elif  age >= 6:
#    print 'teenager'
#else:
#    print 'kid'

#names = ['Michael','Bob','Tracy']
#for name in names:
#    print name

#sum = 0
#for x in [1,2,3,4,5]:
#    sum += x
#print sum

#sum = 0
#for x in range(101):
#    sum += x
#print sum

sum = 0
n = 99
while n > 0:
    sum = sum + n
    n = n - 2
print sum

birth = int(raw_input('birth:'))
if birth < 2000:
    print '00前'
else:
    print '00后'
